Odessa gunman bought weapon through private sale: Sources

ODESSA, Texas -- The gunman who killed seven people and wounded 23 more with the use of an assault-style rifle in Odessa, Texas acquired his weapon through a private sale loophole, multiple law enforcement sources told ABC News.

Authorities stated the suspect, Seth Ator, was considered a "prohibited person" barred by law from purchasing or possessing a firearm because he was diagnosed as being mentally ill. It was further confirmed by Texas Gov. Greg Abbott, who said the shooter failed a background check.

According to federal and state sources, the private sale law allows the sale or purchase of handguns and rifles, including the semi-automatic AR-15 assault style rifles.

The seller may not sell a weapon if he or she knows the buyer is flagged, but is under no obligation to do a background check or ask about the buyer's status.

Odessa Police Chief Michael Gerke said Ator had been fired Saturday from Journey Oilfield Services. He said both Ator and the company called 911 after the firing, but that Ator was gone by the time police showed up. FBI special agent Christopher Combs says Ator's statements on the phone were "rambling."